Appendix f: convert voltage/current to dac, Appendix f – B&B Electronics ZXT9-IOA-KIT - Manual User Manual
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Appendix F: Convert Voltage/Current to DAC
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Manual Documentation Number: ZXTx-IO-x-4113m
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In Zlinx Xtreme I/O modules, analog inputs are 16 bit and analog outputs are 12 bit. The Modbus register scaling for the analog
inputs and outputs for different selections are shown below:
1. Analog Output (0-10 VDC Selection):
Voltage Full Range = 0-10VDC
DAC full range is 4096 counts
as AO’s are 12Bit (0-4095 range), 4096
Holding Register Value to Send = Voltage Desired * 4096 / 10
(ex) For sending out 2.5V, Holding Register Value = 2.5 * 4096 / 10 = 1024
2. Analog Output (0-5 VDC Selection):
Voltage Full Range = 0-5VDC
DAC full range is 4096 counts
as AO’s are 12Bit (0-4095 range), 4096
Holding Register Value to Send = Voltage Desired * 4096 / 5
(ex) For sending out 2.5V, Holding Register Value = 2.5 * 4096 / 5 = 2048
3. Analog Output (0-20 mA Selection):
Current Full Range = 0-20mA
DAC full range is 4096 counts
as AO’s are 12Bit (0-4095 range), 4096
Holding Register Value to Send = Current Desired * 4096 / 20
(ex) For sending out 10 mA, Holding Register Value = 10 * 4096 / 20 = 2048
4. Analog Output (4-20 mA Selection):
Current Full Range = 4-20mA
DAC full range is 4096 counts
as AO’s are 12Bit (0-4095 range), 4096
Holding Register Value to Send = (Current Desired-4) * 4096 / 16
(ex) For sending out 10 mA, Holding Register Value = (10-4) * 4096 / 16 = 1536
5. Analog Input (0-10 VDC Selection):
Voltage Full Range = 0-10VDC
DAC full range is 65536 counts
as AI’s are 16 Bit (0-65,535 range), 65,536
Input Register Value = Actual Voltage * 65536 / 10
(ex) Input register value for 2.5V = 2.5 * 65536 / 10 = 16384
6. Analog Input (0-5 VDC Selection):
Voltage Full Range = 0-5 VDC
DAC full range is 65536 counts
as AI’s are 16 Bit (0-65,535 range), 65,536